Abductor muscle strengthening in THA patients operated with minimally-invasive anterolateral approach for developmental hip dysplasia

Abstract

Objective: In developmental hip dysplasia (DDH) patients, the chronic dislocation of the femoral head with respect to the true acetabulum determines muscle contracture and atrophy, particularly of the abductor muscles, and leads to secondary osteoarthritis (OA) with severe motor dysfunction, pain and disability. The correct positioning when a total hip replacement (THR) is performed is fundamental to the recovery of gait function. Also, inadequate rehabilitation of the abductor muscles for pelvic stabilisation can be responsible for residual dysfunction. Consensus on a programme for abductor muscle strengthening in these patients is not currently available. The aim of this study was to evaluate the effectiveness of a specific program of exercises for strengthening the abductor muscles in these patients. Methods: A multicentre, prospective, randomised clinical trial was carried out in an outpatient rehabilitation setting on 103 patients given THR for DDH through a minimally invasive anterolateral approach. Patients were randomly divided into a Study Group, including 46 patients, and a Control Group, including 57 patients. All patients underwent standard early postoperative rehabilitation. In addition, the Study Group were given an extra 2-week rehabilitation once full weight-bearing on the operated limb was allowed, aimed at strengthening the abductor muscles. All patients were evaluated preoperatively, and at about 3 and 6 months postoperatively. Clinical measures (lower limb-length differences, hip range of motion, abductor muscle strength), and functional measures (WOMAC, HHS, 10mt WT, SF-12) were taken. Results: Hip range of motion and functional outcome measures showed a progressive improvement at follow ups in both groups, significantly higher in the Study Group. In particular, abductor strength at 6 months post-op improved by 92.5% with respect to 35.7% in the Control Group. Conclusion: In addition to standard rehabilitation, a rehabilitation programme for strengthening the gluteal muscles in DDH patients who underwent THR determined an increase in muscle strength that improved functional performance and patient satisfaction.

Risk of Dislocation After Total Hip Arthroplasty in Patients with Crowe Type IV Developmental Dysplasia of the Hip

“…Furthermore, we believe that preoperative and postoperative improvement in abductor muscle strength plays an important role in preventing postoperative dislocation in Crowe type IV patients, since it has been reported that an extended rehabilitation program for strengthening the gluteal muscles in DDH patients after THA can be effective. However, the rehabilitation protocol for Crowe type IV DDH patients needs to be further investigated.…”

Effects of Hip Abductor Strengthening on Musculoskeletal Loading in Hip Dysplasia Patients after Total Hip Replacement

“…We compared gait analysis measurements, joint contact forces and muscle forces of the hip between a group of patients who performed the specific rehabilitation protocol and another group of patients who performed standard rehabilitation only, in the operated and contralateral limb. We tested the hypothesis that a higher improvement in clinical and functional outcome in patients after hip abductor strengthening, as shown recently [10], would result in differences in muscle and joint forces compared to patients who performed standard rehabilitation only.…”

“…Recently, we have evaluated the effects of a program of abductor exercises on a population of DDH patients through a randomized prospective study [10]. We found a significantly higher improvement in clinical and functional scores at follow-ups of a Study Group that performed a specific muscle strengthening program, compared to a Control Group that performed standard postoperative rehabilitation only.…”

“…Thirty DDH patients were randomly selected from a total of 110 recruited previously within a multicentric clinical trial [10] about the effects of a strengthening abductor program in functional performance and patient's satisfaction. The 30 patients were scheduled for gait analysis at a follow-up of at least 6 months after THR [19][20][21].…”

“…All patients were operated with a minimally invasive anterolateral approach for osteoarthritis secondary to DDH [10], and treated with the same cementless hip implant. Preoperative planning was carried out with HipOp-Plan software (http://www.hipopplan.com/), which allows patient-specific, interactive and user-friendly positioning of the prosthesis components.…”